Research On Complex System Reliability Analysis Based On Multiple Failure Modes

With the high integration of the system and the complexity of the operating environment,the complex system reliability is characterized by complex structure,diversity of failure modes and nonlinear operation state.The traditional reliability analysis method is based on a large number of failure data.Because of the long life and high reliability of the complex system,the traditional reliability analysis method is obviously impractical.This paper analyzed the system failure mode and failure mechanism,studied correlation and competition among multiple failure modes in complex systems,Based on the reliability theory,the reliability analysis method of complex system with multiple failure modes is studied.Firstly,the current research situations of degradation failure reliability analysis and multiple failure mode reliability analysis were reviewed.The basic theory of reliability was introduced and the degradation failure,shock failure and catastrophic failure were described.This paper analyzed the correlation between different failure modes and given a general model of competing failure based on multiple failure modes,which established foundation for the reliability analysis of multiple failure modes in complex systems.Secondly,in view of the situation of two-stage or more-stage in the system,the change point problem of two-stage degradation failure process was analyzed and the general model of Wiener stochastic degradation process and Gamma stochastic degradation process was given.According to the degradation characteristics of complex systems,this paper analyzed two-stage degradation process based on Wiener stochastic process and established two-stage Wiener degradation process including change point.The maximum likelihood method was used to estimate change point and unknown parameters.Then,System reliability was evaluated.Thirdly,the complex systems exists multi-degradation failure and the catastrophic failure,multiple failure modes often show competing failure.A reliability assessment method of the competing failure during multi-degradation failure and the catastrophic failure was proposed.Covariance was used to analyze the dependence and the degree of correlation during multivariate degradation information,reliability assessment model of multi-degradation mode was developed.The conditional probability of catastrophic failure under the degradation data was developed to analyze the effect of degradation failure on catastrophic.Reliability assessment model of competition failure was developed through the joint probability distribution function of multi-degradation mode and catastrophic failure.An example of the failure data of aero engine verified the effectiveness of proposed method.Finally,the reliability management PDCA cycle and DMAIC reliability management method were analyzed.The civil aircraft system as an example,research on complex system reliability management method,to some extent,complex system reliability management level was improved.The research provided a method for reliability analysis based on multiple failure modes in complex system and studied on the two-stage degradation process,change point,multiple failure modes,competing failure,reliability analysis and other related theories and technical problems.The research results of this paper will play a guiding significance and engineering value for the complex systems reliability analysis and evaluation.